HP 8566B Adjustment Manual page 290

17. 20/30 Loop Phase Lock Adjustments
3-150 Adjustments
20. Press CmGHz_ on the second spectrum analyzer. Set the controls
of the second spectrum analyzer as follows:
CENTER FREQUENCY . . . . . . . . . . . . . . . . . . . . . . . . . . . . .300 MHz
FREQUENCY SPAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .500 MHz
REFERENCE LEVEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +3 dBm
21. Set the dc power supply for an output of + 16.0 f 0.1 Vdc.
Connect the positive lead of the dc power supply to AlOAlTP3
and the negative lead to the RF Section chassis (ground).
(
22. Press MARKER
PEAK SEARCH
The output frequency of the PLLl VCO should be 310 MHz f 10
MHz as indicated by the marker on the display of the second
spectrum analyzer. If it is not, remove the metal shield from
AlOAl PLLl VCO Assembly and increase or decrease the spacing
between turns of coil AlOAlL4.
The PLLl VCO frequency is increased by spreading
of A10AlL4 apart (decreasing the inductance), and decreased
by compressing the turns of AlOAlL4 together (increasing the
inductance). Adjust AlOAlL4 for a PLLl VCO output frequency
of approximately 308 MHz, since the metal shield increases the
23. Set the dc power supply for an output of +4.0 f 0.1 Vdc.
[
24. Press MARKER
PEAK SEARCH
The frequency of the PLLl VCO output signal should drop below
200 MHz, and the power level should be at least -7 dBm, as
indicated by the marker on the display of the second spectrum
analyzer.
25. Repeat steps 21 through 24 as necessary until no further
adjustment is required.
26. Set the RF Section LINE switch to STANDBY. Replace the metal
shield on AlOAl PLLl VCO Assembly if it was removed, and
reinstall AlOAl PLLl VCO Assembly in the RF Section. Reconnect
the cable 1 (brown) to AlOA5J5 SCAN .l-5 MHz OUT and the
cable 5 (green) to AlOAlJ2 OUT 20-30 MHz.
27. Remove AlOA3 PLLl IF Assembly from the RF Section, and
install it on an extender board. Reconnect the cable 6 (blue)
to AlOA4J2 OUT 160-166 MHz. Leave the cable 4 (yellow)
disconnected from AlOAlJ3 OUT 200-300 MHz, and the cable 3
(orange) disconnected from AlOA3J3 OUT PLLl IF.
28. Use a BNC to SMB Snap-on Test Cable to
the second spectrum analyzer to AlOA3J3 OUT PLLl IF
)
on the second spectrum analyzer.
]
on the second spectrum analyzer.
connect the RF INPUT of
the turns